Author Archives: John F. Lindner

I’ve been fascinated by aperiodic tilings of the plane since Martin Gardner first wrote about them in Scientific American. In the 1960s, Robert Berger discovered a set of 20 426 prototiles or tile-types that can tile the plane but only with no … Continue reading →
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As a kid, I devoured the pages of Popular Science magazine and was fascinated by the quest for human-powered flight: Was a flying bicycle possible? In the mid 1970s, I read that aerospace engineer Paul MacCready had assembled a team … Continue reading →
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There is a fantastic castle in the sky, built in free fall, brick-by-brick. It derives its energy from sunlight and recycles its water. Sealed against a vacuum, its inhabitants float and glide through its passageways as the sun rises and … Continue reading →
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1930s businessman Edgar Kaufmann Sr. and his family lived in Pittsburgh Pennsylvania. Kaufmann owned a rural retreat outside the city and wanted a weekend home there. He assumed his 67-year-old architect would design the home with a good view of … Continue reading →
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The tallest structure in the world since 2008, Burj Khalifa (or Khalifa Tower) is the fantasy skyscraper of my childhood. Designed and engineered by Adrian Smith and Bill Baker of Skidmore, Owings & Merrill (SOM), it is an architectural and … Continue reading →
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Chaotic systems are extremely sensitive to the initial conditions and parameters that define them. Minute perturbations of the parameters can even convert chaotic motion to periodic motion. This alliance between control methods and physics — cybernetical physics — opens the … Continue reading →
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Momentum conservation (or Newton’s third law) ensures two-way or bidirectional coupling for typical media like guitar strings and spring mattresses. One-way or unidirectional coupling enables the propagation of solitary waves or solitons with diverse behaviors in otherwise dissipative media, but … Continue reading →
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Wind is free and ubiquitous and can be harnessed in multiple ways. We recently published an article in the Physical Review demonstrating mechanical stochastic resonance in a tabletop experiment that harvests wind energy to amplify weak periodic signals detected via the movement … Continue reading →
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Why has SpaceX chosen methane to fuel its Raptor rocket engine? Robert Goddard’s first rockets used liquid oxygen O2 or LOX and gasoline. The Saturn V moon rocket first stage used LOX and refined kerosene. The Saturn V second stage used … Continue reading →
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In 1971 during Apollo 15’s return from Earth’s moon, astronaut Al Worden performed the first deep space walk nearly 200 000 miles from Earth to recover external service module film canisters that had mapped the lunar surface. Worden was able … Continue reading →
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